Prettier plugin for formatting enums removes comments — how to preserve the original printer? - Stack Overflow

I created a custom printer for Prettier to format enum declarations in a specific way. However, when using my custom printer, all comments inside the enum are removed.

I want my printer to only modify specific parts of the formatting (e.g., alignment of the = operator) while preserving the original Prettier behavior for everything else, including comments.

Is there a way to extend the default Prettier printer instead of fully replacing it?

I implemented a custom printer, but it seems to override the entire printing process, causing:

• Loss of comments inside enum.

• Application of different formatting rules, such as trailing commas and spacing changes.

Here is the relevant code:

import { AstPath, Doc, ParserOptions, doc } from 'prettier'

const { join, group, indent, hardline } = doc.builders

type TSEnumMember = {
  id: { name: string }
  initializer?: unknown
}

type TSEnumDeclaration = {
  type: 'TSEnumDeclaration'
  id: { name: string }
  members: TSEnumMember[]
}

export const printEnum = (path: AstPath<TSEnumDeclaration>, options: ParserOptions, print: TCallbackPrint): Doc => {
  const maxMemberLength = path.node.members.reduce((max, member) => Math.max(max, member.id.name.length), 0)

  const memberDocs = path.map((memberPath) => {
    const member = memberPath.node
    const spacing = ' '.repeat(maxMemberLength - member.id.name.length)

    if (member.initializer !== undefined) {
      return [
        `${member.id.name}${spacing} = `,
        memberPath.call(print, 'initializer'),
        ',',
      ]
    }

    return [member.id.name, ',']
  }, 'members')

  const joinedMembers = join(hardline, memberDocs)

  return group([
    `enum ${path.node.id.name} {`,
    indent([hardline, joinedMembers]),
    hardline,
    '}',
  ])
}

GitHub repo: